Sealed Circuit Breaker

ABSTRACT

A sealed electrical enclosure used in hazardous locations for enclosing circuit breakers having a bottom housing and a top housing with a labyrinth seal or joint formed therebetween, the bottom housing adapted to receive one or more circuit breakers, a first metal bus extending from a point internal to the bottom housing through a first end wall to a point external thereto, and a second metal bus extending from a point internal to the bottom housing through a second end wall to a point external to thereto, where the first and second metal buses are adapted to contact first and second electrical terminals of a circuit breaker when placed within the bottom housing, and a first vent positioned on the top housing for dissipating pressure buildup, wherein the top housing is removably secured to the bottom housing to allow for removal and replacement of a circuit breakers within the housing.

RELATED APPLICATION

This application is a continuation of prior U.S. patent application Ser.No. 12/283,053, filed on Sep. 9, 2008, which claims priority to IndianPatent Application 1673/MUM/2008 filed Aug. 6, 2008. U.S. patentapplication Ser. No. 12/283,056 and Indian Patent Application1673/MUM/2008 are hereby incorporated by reference.

BACKGROUND

1. Field of the Application

This application relates generally to sealed electrical enclosures foruse in hazardous locations for a variety of electrical components, suchas circuit breakers, motor switches, GFI devices, and photocells.

2. Description of the Related Art

Traditionally, in North America, to use circuit breakers in a hazardous(classified) area, standard circuit breakers are placed in a cast metalhousing such as aluminum, wherein the cast metal housing is bolted shut.In such an arrangement, the circuit breaker switches may be manipulatedthrough a cast metal door that is bolted to the cast metal housing. InNorth America, this construction is suitable for Class I Division 1 andClass I Division 2 applications. A drawback of this arrangement is thatthe cast iron enclosures are heavy and cumbersome. Furthermore, it canbe time consuming and laborious to remove the often extensive number ofbolts from the cast metal housing to access the circuit breakers within.Thus, replacing circuit breakers using enclosures with this constructioncan be time consuming and costly.

Alternatively, in Europe, in accordance with IEC methodology,traditionally each circuit breaker or other electrical device isseparately and permanently sealed (often potted in epoxy) to provide aflame proof device. Each flame proof sealed circuit breaker orelectrical device is then typically placed in a non-metallic or sheetmetal enclosure. Each sealed circuit breaker typically has a handle orswitch that extends through a door of the non-metallic or sheet metalenclosure to allow for manipulation of the handle or switch. In theevent that a circuit breaker needs to be replaced, the flame proofcircuit breaker is removed, and a replacement flame proof circuitbreaker installed. A drawback to this methodology is that it is morecostly to replace each separately sealed flame proof circuit breakersthan it is to replace non-flame proof circuit breakers.

There has been an increased demand for sealed breakers in North America.Thus, there is a need to provide an electrical enclosure for use inhazardous (classified) locations that can provide for the removal andreplacement of circuit breakers or other electrical components from areusable electrical enclosure. For purposes of this application the term“hazardous locations” and “hazardous (classified) locations shall meanareas classified by the National Electric Code (NEC), such as NEC ClassI, Division 1 areas.

SUMMARY

The present application provides a sealed electrical enclosure for usein hazardous locations for enclosing circuit breakers or otherelectrical components comprising a bottom housing and a top housingpositioned thereabove; a labyrinth seal or joint being formed betweenthe bottom housing and the top housing; the bottom housing adapted toreceive a plurality of circuit breakers or other electrical components;and a first metal bus extending from a point internal to the bottomhousing through a first end wall to a point external to the bottomhousing; and a second metal bus extending from a point internal to thebottom housing through a second end wall to a point external to thebottom housing; where the first metal bus and the second metal bus areadapted to contact first and second electrical terminals of a firstcircuit breaker placed within the bottom housing; and a first actuatingmechanism positioned on the top housing adapted for manipulating one ormore switches of circuit breakers or electrical components positionedwithin the bottom housing; and a first vent positioned on the tophousing for dissipating heat or pressure buildup within the housing; andwherein the top housing is removably secured to the bottom housing toallow for removal and replacement of circuit breakers or otherelectrical components within the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are described herein withreference to the drawings, in which:

FIG. 1 is a perspective view of an embodiment of a sealed electricalenclosure;

FIG. 2 is a perspective view of an embodiment of the sealed electricalenclosure of FIG. 1 adapted for operation externally from an electricalpanel box;

FIG. 3 is a top view of the sealed electrical enclosure of FIG. 2;

FIG. 4 is a perspective cut-away view of the sealed electrical enclosureof FIG. 1;

FIG. 5 is a sectional view of the sealed electrical enclosure of FIG. 1;

FIG. 6 is an exploded view of a sealed electrical enclosure;

FIG. 7 is a top perspective view of the bottom housing of the sealedelectrical enclosure of FIG. 1;

FIG. 8 is a close up view of a portion of the bottom housing of FIG. 7;

FIG. 9 is a top perspective view of the top housing of the sealedelectrical enclosure of FIG. 1;

FIG. 10 is a partial cut-away view of a sealed electrical enclosure;

FIG. 11 is a cut-away view of a portion of the actuating mechanism ofthe sealed electrical enclosure of FIG. 1;

FIG. 12 is a perspective view of a sealed electrical enclosure;

FIG. 13 is a perspective view of two sealed electrical enclosurespositioned within an electrical panel box;

FIG. 14 is a perspective view of four sealed electrical enclosurespositioned within an electrical panel box;

FIG. 15 is a perspective view of various circuit breakers that may bepositioned within the sealed electrical enclosure of FIG. 1;

FIG. 16 is a perspective view of various types of circuit breakers thatmay be positioned within the sealed electrical enclosure of FIG. 1; and

FIG. 17 is a perspective view of four sealed electrical enclosurespositioned on an electrical panel.

DETAILED DESCRIPTION

Referring to FIG. 1, a perspective view of sealed electrical enclosure10 is shown having bottom housing 12 and top housing 14, with tophousing 14 being removably secured to bottom housing 12 using bolts 22.Of course, it is not required to use bolts, but any other suitable meansof removably securing top housing 14 to bottom housing 12 could be usedsuch as clips, screws, clamps, latches, etc. Preferably bottom housing12 and top housing 14 are comprised of hard non-conductive material suchas a plastic or composite material, most preferably Solvay IXEF 1022 orRyton R-4.

Sealed electrical enclosure 10 further includes an actuating mechanism20 that allows for the manipulation of the switches of circuit breakersor other electrical components positioned within the enclosure 10. Theactuating mechanism 20 provides for linear actuation, although rotaryactuation could be used as well. Enclosure 10 may be used to housevarious types of circuit breakers and other electrical components suchas circuit interrupters, motor switches, GFI devices, and photocells toname a few. Further, enclosure 10 may be used to house both IEC and NECapproved products.

As shown in FIG. 1, electrical buses 30, 32, and 34 extend from a pointwithin the enclosure 10 through a first sidewall 40 to a point externalto the enclosure 10 as shown. In this manner, circuit breakers or otherelectrical products may be positioned entirely within enclosure 10 andelectrically connected to electrical terminals in an electrical panelbox (not shown). Using the configuration shown, sealed enclosure 10provides for a flame proof housing for use in Class I, Division 2applications, and in hazardous locations or areas classified bydivisions or zones such as Class I, Zone 1.

With the configuration of sealed electrical enclosure 10, by removingbolts 22, top housing 14 may be removed from bottom housing 12. As aresult, the circuit breakers or other electrical products positionedwithin the enclosure 10 may be removed and replaced, while allowingsealed electrical enclosure 10 to be reused.

FIG. 2 discloses sealed electrical enclosure 10, with external actuatingmechanism 20 further including knobs or extensions 50 that allow theenclosure 10 to be positioned within an electrical panel box (notshown), and still allow for the actuating mechanism to manipulate theswitch of a circuit breaker or other electrical device positioned withinenclosure 10.

FIG. 3 is a top view of the enclosure 10 shown in FIG. 2 showing anotherview of knobs or extensions 50 positioned on top housing 14.

FIG. 4 shows a sectional, perspective view of sealed electricalenclosure 10 with actuating mechanism 20 on top housing 14 including aslidable rigid rod 60 as well as a switch manipulator 70 attachedthereto for manipulating switch 74 of a circuit breaker or otherelectrical device.

FIG. 5 shows a side sectional view of enclosure 10 and provides anotherview of actuating mechanism 20 including slidable rigid rod 60 that maybe moved in a slidable manner within top housing 14, as well as switchmanipulator 70 attached thereto for manipulating switch 74. FIG. 5 alsoshows electrical bus 30 extending from a point within bottom housing 12through a first sidewall 40 of bottom housing 12 to a point external toenclosure 10. Similarly, electrical bus 31 is shown extending from apoint within bottom housing 12 through second sidewall 42 of bottomhousing 12 to a point external to enclosure 10. This configurationhaving electrical buses 30 and 31 extending through the first and secondsidewalls 40 and 42 respectively allows a circuit breaker to bepositioned within the enclosure 10 with a first electrical terminal ofthe circuit breaker contacting bus 30 inside of the bottom housing 12and a second electrical terminal of the circuit breaker contacting bus31 inside of the bottom housing 12 and thereby providing an electricalconnection via bus 30 and 31 to a point external of enclosure 10 toallow further electrical connection to electric terminals within anelectrical panel box.

This configuration allows for the circuit breakers to be completelyenclosed with the enclosure 10, but provides for electrical connectionof the circuit breaker to other electrical terminals external to thebox. In this manner, the enclosure 10 provides a flame proof enclosurefor use in hazardous (classified) areas with the manipulation of theswitch 74 external to the enclosure. With such a design, the circuitbreakers within the enclosure 10 do not themselves need to be flameproof and can be more easily removed and replaced simply by removing tophousing 14 while allowing sealed enclosure 10 to be reused.

With respect to FIGS. 1 and 5, buses 30-35 are preferably positionedwithin their respective sidewalls by a molding process. One method ofmolding the buses into the sidewalls is by placing the buses into themold before the molten plastic fills the mold.

FIG. 6 shows an exploded view of sealed enclosure 10. In thisembodiment, there are shown three separate actuating mechanisms 20 eachusing a slidable rigid rod 60 with bolts 22 shown on top housing 14. Itshould be noted that while slidable rigid rod 60 is preferably of around cross-section, it could also have a square, hexagonal, oval orother cross-section. Thus, the term “rod” is not limited to a rod havinga round cross-section, but encompasses any other suitable geometry aswell.

FIG. 7 shows a perspective view of bottom housing 12, showing electricalbuses 30, 32, and 34 extending through first sidewall 40 from a pointwithin the bottom housing 12. FIG. 7 further shows buses 31, 33, and 35positioned within bottom housing 12 into (and through) second sidewall42 to a point external to the enclosure 10. Bottom housing 12 alsoincludes labyrinth channel 80 that is adapted to receive a correspondinglabyrinth extension of the top housing 14 (not shown) to form alabyrinth seal or joint, or flame path. A serrated joint could also beused. Also shown in a bottom wall of bottom housing 12 is a ventingplate or vent 82 that allows for pressure and heat to dissipate withinthe enclosure. Vent 82 is preferably formed of a sintered bronzematerial. Other materials could be used as the vent material such asstainless steel or aluminum.

FIG. 8 shows a close up view of a portion of bottom housing 12 moreclearly showing labyrinth channel 80.

FIG. 9 shows a perspective view of top housing 14 and shows a ventingplate or 84 vent positioned on the top thereof. Similar to venting plate82 shown in FIG. 7, vent 84 allows for pressure and heat to dissipatewithin the enclosure. Vent 84 is also preferably formed of a sinteredbronze material.

FIG. 10 is a partial cut-away view of sealed electrical enclosure 10showing knobs or extensions 50 positioned on actuating mechanism 20. Inthis Figure, switch manipulator 70 is shown connected to slidable rigidrod 60 for manipulating switch 74 of a circuit breaker or otherelectrical component.

FIG. 11 shows a close up view of slidable rigid rod 60 that slidablyextends through bushing 62 that is threadably connected to actuatingmechanism 20. Preferably, there is a very close tolerance between rod 60and bushing 62 to eliminate any flame path from within the enclosure 10.Preferably a 0.002 maximum clearance is used.

FIG. 12 shows a perspective view of sealed electrical enclosure 10 withbottom housing 12 and top housing 14 and FIG. 13 shows electrical panelbox 90 with two sealed enclosures 10 positioned therein.

FIG. 14 shows four sealed enclosures 10 alternately positioned within anelectrical panel box 94.

FIG. 15 shows various circuit breakers or electrical devices that may bepositioned within the enclosure 10. Numeral 110 refers to a one-pole NECcircuit breaker design, while numeral 122 refers to a three-pole NECcircuit breaker design. Numeral 100 references IEC circuit breakers orinterrupters that also may be positioned within enclosure 10. Of course,many other kinds of circuit breakers could be used with this enclosure,including two pole designs.

The present invention is shown in a particular configuration forillustrative purposes only. The enclosure 10 may have varying geometriesto accommodate various sized circuit breakers and electrical components.It is contemplated that the enclosure 10 may be used with all of theF-Series or F-frame circuit breaker skus currently available fromCutler-Hammer, ranging up to 225 amps, and covering 1, 2, and 3 poleversions. It is also contemplated that the enclosure 10 may be used withall of the QC Series circuit breaker skus currently available fromCutler-Hammer, ranging up to 100 amps, and covering 1, 2, and 3 poleversions. With some possible modification to the geometry of thehousing, it is contemplated that the present design would be suitablefor use for many different types of available or yet to be releasedcircuit breakers.

FIG. 16 discloses bottom housing 12 along with various circuit breakers118, 128, 138, 148, 168, and 178 that may be positioned within bottomhousing 12. For example, circuit breaker 118 is of a 3 pole varietyhaving a single switch. When circuit breaker 118 is properly positionedwithin bottom housing 12, electrical terminal 124 of the circuit breaker118 contacts bus 34 within the bottom housing 12, electrical terminal122 contacts bus 32 within the bottom housing 12, and electricalterminal 120 contacts bus 30 within the bottom housing 12. Similarly,electrical terminal 125 of circuit breaker 118 contacts bus 35 withinthe bottom housing 12, electrical terminal 123 contacts bus 33 withinthe bottom housing 12, and electrical terminal 121 contacts bus 31 (notshown) within the bottom housing 12. In this manner, the enclosure 10may accommodate a 3 pole circuit breaker having a single switch.

FIG. 16 also discloses that more than one circuit breaker may beaccommodated. For example, circuit breakers 128, 138, and 148, all of a1 pole one switch variety may all be positioned within the bottomhousing 12. Circuit breaker 148 may be properly positioned within bottomhousing 12 so that electrical terminal 134 of the circuit breaker 148contacts bus 34 within the bottom housing 12 and electrical terminal 135contacts bus 35 within the bottom housing 12. Similarly, circuit breaker138 may be properly positioned within bottom housing 12 next to circuitbreaker 148 so that electrical terminal 132 of the circuit breaker 138contacts bus 32 within the bottom housing 12 and electrical terminal 133contacts bus 33 within the bottom housing 12. Additionally, circuitbreaker 128 may be properly positioned within bottom housing 12 next tocircuit breaker 138 so that electrical terminal 130 of the circuitbreaker 128 contacts bus 30 within the bottom housing 12 and electricalterminal 131 contacts bus 31 (not shown) within the bottom housing 12.In this manner, the enclosure may accommodate three separate circuitbreakers, in this case each being of the one pole, one switch variety.

FIG. 16 further discloses that the sealed enclosure may accommodatecircuit breakers of varying types and dimensions. For example, circuitbreaker 168, a single pole single switch type, may be positioned withinthe bottom housing 12 so that electrical terminal 154 of the circuitbreaker 168 contacts bus 34 within the bottom housing 12 and electricalterminal 155 contacts bus 35 within the bottom housing 12. Additionally,circuit breaker 178, a 2 pole, single switch type, may be properlypositioned within bottom housing 12 next to circuit breaker 168 so thatelectrical terminal 152 of the circuit breaker 178 contacts bus 32within the bottom housing 12 and electrical terminal 153 contacts bus 33within the bottom housing 12, while electrical terminal 150 contacts bus30 within the bottom housing 12 and electrical terminal 151 contacts bus31 (not shown) within the bottom housing 12. In this manner, theenclosure may accommodate two different circuit breakers of differentgeometries and design.

It will be appreciated that the enclosure could be enlarged to houseadditional circuit breakers and its geometry could be modified toaccommodate circuit breakers of varying size.

The sealed enclosure described herein may be used in hazardous(classified) locations including Class I, Division 2 and Class I, Zone 1environments, and it is believed that it is arc flash proof as well.

FIG. 17 discloses four sealed electrical enclosures 10 mounted on anelectrical panel 150. It is contemplated that enclosures 10 may bemounted in suitable electrical panels boxes, including stainless steel,plastic, and thin-wall cast panel boxes.

While certain features and embodiments of the present application havebeen described in detail herein, it is to be understood that theapplication encompasses all modifications and enhancements within thescope and spirit of the following claims.

1. A sealed electrical enclosure for use in hazardous locations forenclosing circuit breakers or other electrical components comprising: abottom housing having a first end wall and a second end wall oppositethe first end wall; a top housing positioned above the bottom housing; aserrated joint being formed between the bottom housing and the tophousing; the bottom housing adapted to receive one or more circuitbreakers or other electrical components; a first metal bus extendingfrom a point internal to the bottom housing through the first end wallto a point external to the bottom housing; a second metal bus extendingfrom a point internal to the bottom housing through the second end wallto a point external to the bottom housing; where the first metal bus andthe second metal bus are adapted to contact first and second electricalterminals of a first circuit breaker when placed within the bottomhousing; a first actuating mechanism positioned on the top housingadapted for manipulating one or more switches of circuit breakers orelectrical components positioned within the bottom housing; and whereinthe top housing is removably secured to the bottom housing to allow forremoval and replacement of circuit breakers or other electricalcomponents within the housing.
 2. The sealed electrical enclosure ofclaim 1, further including a third metal bus extending from a pointinternal to the bottom housing through the first end wall to a pointexternal to the bottom housing; a fourth metal bus extending from apoint internal to the bottom housing through the second end wall to apoint external to the bottom housing; where the third metal bus and thefourth metal bus are adapted to contact the first and second electricalterminals of a second circuit breaker when placed within the bottomhousing.
 3. The sealed electrical enclosure of claim 1, wherein thesealed enclosure is adapted for installment within an electrical panelbox.
 4. The sealed electrical enclosure of claim 3, wherein a pluralityof the sealed enclosures are positioned within an electrical panel box.5. The sealed electrical enclosure of claim 2, wherein the first, secondthird, and fourth buses are set in the first and second sidewalls of thebottom housing during a molding process.
 6. The sealed electricalenclosure of claim 1, wherein the bottom housing is adapted to receiveF-frame circuit breakers.
 7. The sealed electrical enclosure of claim 1,wherein the bottom housing is adapted to receive QC-series circuitbreakers.
 8. A sealed electrical enclosure for use in hazardouslocations for enclosing circuit breakers or other electrical componentscomprising: a bottom housing having a first end wall and a second endwall opposite the first end wall; a top housing positioned above thebottom housing; a labyrinth seal or joint being formed between thebottom housing and the top housing; the bottom housing adapted toreceive one or more circuit breakers or other electrical components; afirst metal bus extending from a point internal to the bottom housingthrough the first end wall to a point external to the bottom housing; asecond metal bus extending from a point internal to the bottom housingthrough the second end wall to a point external to the bottom housing;where the first metal bus and the second metal bus are adapted tocontact first and second electrical terminals of a first circuit breakerwhen placed within the bottom housing; a first actuating mechanismpositioned on the top housing adapted for manipulating one or moreswitches of circuit breakers or electrical components positioned withinthe bottom housing; and wherein the top housing is removably secured tothe bottom housing to allow for removal and replacement of circuitbreakers or other electrical components within the housing.
 9. Thesealed electrical enclosure of claim 8, further including a third metalbus extending from a point internal to the bottom housing through thefirst end wall to a point external to the bottom housing; a fourth metalbus extending from a point internal to the bottom housing through thesecond end wall to a point external to the bottom housing; where thethird metal bus and the fourth metal bus are adapted to contact thefirst and second electrical terminals of a second circuit breaker whenplaced within the bottom housing.
 10. The sealed electrical enclosure ofclaim 8, wherein the sealed enclosure is adapted for installment withinan electrical panel box.
 11. The sealed electrical enclosure of claim10, wherein a plurality of the sealed enclosures are positioned withinan electrical panel box.
 12. The sealed electrical enclosure of claim 9,wherein the first, second third, and fourth buses are set in the firstand second sidewalls of the bottom housing during a molding process. 13.The sealed electrical enclosure of claim 8, wherein the bottom housingis adapted to receive F-frame circuit breakers.
 14. The sealedelectrical enclosure of claim 8, wherein the bottom housing is adaptedto receive QC-series circuit breakers.